> Do you ever hit the brake pedal outside emergency situations?

Yes. BTW, you mostly use B-mode on the highway. You don't get any advantage in stop and go traffic.

> What is the rate of braking when you take take your foot off the pedal?

It is greater than aerodynamic friction. What I like is that in emergency situations where you do brake, it brakes faster since in the interval between your foot on the accelerator and your foot hitting the brake, it's already braking.

> Does it take into account the car in front of you?

There may be cars that do this (Tesla?) but not the Leaf and probably not the Bolt.

I get a lot of advantage out of one-pedal driving in a Model S in stop and go, both urban and highway.

One thing that makes me sad about Tesla's adaptive cruise control is that it's not as good as I am at never touching the real brakes -- it doesn't anticipate very well, and waits until it gets within 2-3 car-lengths (settable) before it even thinks about braking.

Yeah, I was on 880 and I saw a Tesla doing that. I knew it wasn't a human decision. It was too precise and at the same time unnecessarily disconcerting. A human would have been less precise but would have dipped in speed well before 2-3 car lengths and probably would have taken the opportunity to zip around the car in front.

> It is greater than aerodynamic friction.

Is it comparable to engine braking in a manual transmission vehicle in at cruising RPMs?

Self-reply: It is adjustable in most electric cars at, variously, up to 0.2g or 24 kW of regenerative braking power. This is actually significantly higher than typical engine braking in a gas powered manual transmission vehicle. Engine braking can keep up with low-power, light braking to adjust following distance on highways, and can limit acceleration on a downhill if you downshift to force the motor to run at 3/4k RPMs on a steep hill, and can eventually bring a vehicle to a stop. Regenerative braking can be equivalent to typical braking forces for day-to-day driving, depending on battery capacity and charge level allowing the required power dissipation to be in the range of safe charging rates.

(Note: By "Engine braking" I'm referring to throttle retardation in a typical non-diesel engine, not jake brakes on big diesels. I have no idea how powerful those are.)

> It is greater than aerodynamic friction.

Sure, but how much greater? How often do you find yourself wishing to break faster?

I would use the hell out of this for situations where I normally engine brake in a gasoline-powered vehicle. You can basically harvest energy from the change in gravitational potential energy to kinetic energy as you're falling downhill.

One of the things that sucks about my new truck is that 3rd gear is so efficient that I can no longer engine brake on many of the grades where I was able to do so in the past. It's a much less comfortable driving situation to have to brake periodically on the downhill.

Yes you use the brakes for quick stops.

You can coast, to do that you just keep your foot down enough to keep the regeneration from kicking in.

There's no free lunch. You don't recover meaningful energy by regenerating vs. coasting over the same distance. What you do recover is energy that would otherwise go into the air as heat in braking situations.

Thanks.

> You don't recover meaningful energy by regenerating vs. coasting over the same distance.

In fact, you lose net energy if you regeneratively break and then accelerate (vs just coasting) because it's only 80% efficient. So if the "default" position of the pedal is to be braking, rather than coasting, I naively expect it to induce more braking followed by more acceleration, wasting net energy.

Your expectation isn't true for the way I drive, at least. With one pedal driving, you don't really know if you're accelerating or braking, unless you're braking enough that your foot lifts from the pedal... or you look at the dashboard. I find that when traffic is heavy, I spend a lot of time slightly accelerating and slightly braking, while keeping the distance between my car and the one in front of me.

That could easily cause someone else to rear end you. Braking in excess of rolling should require the use of the brake pedal.

If someone rear ends you because you have B-mode or one pedal enabled then they're following way too close to begin with. Way too close and/or not paying attention at all. B-mode doesn't slam on the brakes. It engages regen to decelerate at perhaps a greater rate than rolling resistance.

It's the same as engaging the handbrake while driving. If someone rear ends you when you do that it is your fault, not theirs.

The expectation is that if you reduce speed at a rate associated with braking that your brake lights should come on.

I strongly agree that the brake lights should come on in B-mode. That doesn't happen on the Leaf or on the Volt. That is however a different matter and it should be the law. But B-mode with brake lights is a fine idea.

Or just trigger the break lights.

Yes, that would be the best solution.